Method of forming a sion antireflection film which is noncontaminating with respect to deep-uv photoresists

Abstract

A method of forming a silicon oxynitride antireflection film which is noncontaminating with respect to deep-ultraviolet photoresists (DUV photoresists) on each of a series of silicon semiconductor substrates successively introduced into the same reactor chamber includes a step of plasma-enhanced chemical vapor deposition (PECVD) of a silicon oxynitride antireflection film and treatment of the antireflection film with an oxygen plasma. The reactor chamber is cleaned before the successive introduction of each of the substrates by purging the reactor chamber using an oxygen-free gas plasma and then depositing a silicon oxynitride blanket by plasma-enhanced chemical vapor deposition using precursor gases.

There is claimed:  
     
       1. A method of forming a silicon oxynitride antireflection film which is noncontaminating with respect to deep-ultraviolet photoresists on each of a series of silicon semiconductor substrates successively introduced into a reactor chamber, the method comprising depositing, by plasma-enhanced chemical vapor deposition, a silicon oxynitride antireflection film and treating said antireflection film with an oxygen plasma, wherein said reactor chamber is cleaned before the successive introduction of each of said substrates by: 
       purging said reactor chamber using an oxygen-free gas plasma; and  
       depositing a silicon oxynitride blanket by plasma-enhanced chemical vapor deposition using precursor gases.  
     
     
       2. The method claimed in  claim 1 , wherein said oxygen-free gas plasma is a fluorinated gas plasma. 
     
     
       3. The method claimed in  claim 2 , wherein said fluorinated gas comprises CF 4 , C 2 F 6 , NF 3  or SF 6 . 
     
     
       4. The method claimed in  claim 1 , wherein purging said reactor chamber lasts from 10 to 60 seconds. 
     
     
       5. The method claimed in  claim 1 , wherein said precursor gases comprise N 2 O and SiH 4 . 
     
     
       6. The method claimed in  claim 1 , wherein depositing a silicon oxynitride blanket lasts from 1 to 60 seconds. 
     
     
       7. The method claimed in  claim 1 , wherein purging said reactor consumes all residual oxygen in the chamber. 
     
     
       8. The method claimed in  claim 1 , wherein the plasma-enhanced chemical vapor deposition of a silicon oxynitride antireflection film takes place under the same process conditions as depositing a silicon oxynitride blanket. 
     
     
       9. The method claimed in  claim 1 , wherein the plasma-enhanced chemical vapor deposition of a silicon oxynitride antireflection film takes place under substantially similar process conditions as depositing a silicon oxynitride blanket. 
     
     
       10. The method claimed in  claim 1 , wherein the silicon oxide layer formed from said treatment of said antireflection film with an oxygen plasma inhibits interaction between the nitrogen of the silicon oxynitride antireflection film and the deep-ultraviolet photoresists. 
     
     
       11. The method claimed in  claim 1 , wherein a silicon oxide layer formed from said treatment of said antireflection film with an oxygen plasma inhibits interaction between nitrogen in the silicon oxynitride antireflection film and the deep-ultraviolet photoresists.